Sealing a fine crack in a Jabsco sea toilet pump

[Oily Rag]

I thought I had a slight leak on the bottom seal of the Jabsco pump unit, but on replacing the entire pump, I found a very fine, through-wall crack in the pump cylinder, just below the lower travel position of the piston. If I hadn't added old red antifreeze, I wouldn't have spotted it.

The crack is too fine to take any thick gloop like epoxy, so can anyone suggest something suitable to repair it so I can put it back in the spares box. I have access to both sides of the crack.

 

[Norman_E]

I doubt anything will seal it permanently. Probably best to bite the bullet and buy a new pump.

 

[Rappey]

Soldering iron? Melt over the crack for waterproofing

 

[mikegunn]

I thought I had a slight leak on the bottom seal of the Jabsco pump unit, but on replacing the entire pump, I found a very fine, through-wall crack in the pump cylinder, just below the lower travel position of the piston. If I hadn't added old red antifreeze, I wouldn't have spotted it.

The crack is too fine to take any thick gloop like epoxy, so can anyone suggest something suitable to repair it so I can put it back in the spares box. I have access to both sides of the crack.

You might have access to both sides of the crack but unfortunately not to the internal interfaces. They will be severly contaminated by the anti-freeze and very difficult to clean. There are techniques which can be applied, involving vacuum chambers and Loctite products but they are comparitively expensive and time consuming and would render the item in question beyond economic repair.

Mike

 

[Leighb]

The cost of a complete new pump assembly is not a great deal more than a spares kit. Just buy a new pump and bin the old one.

 

[Momac]

I believe the OP already fitted a new pump.

A new cylinder may be purchased subject to availability but I would suggest a complete pump assembly might be better value


I noticed an alternative brand pump but cant say I have tried it
Nuova Rade Assembled Spare Pump For Manual Toilet Lt-0 And Lt-1 (11535)

 

[LadyInBed]

I believe the OP already fitted a new pump.

You can understand people not reading some of the replies, but you would think that the OP would have been read!
In answer, as Rappey suggests, I would stroke the crack with a clean hot soldering iron or hot rope cutter. Maybe brush on some pipe weld after to smooth it down, assuming it's the type of plastic that will react to pipe weld.

 

[KevinV]

Surely in that position it's a stress fracture? For the cost of the replacement is it really worth faffing with, to then have it fail anyway? Just bin it.

 

[Uricanejack]

Why keep it, nice to have a spare but this one already failed

 

[oldgit]

Nuova Rade Twist n Lock Replacement Toilet Pump Assembly - Suits Jabsco

 

[Robin]

Having replaced the Twist'n lLock pumps complete on our (2) loos, several times over the years we have a few old ones in stock as I suspect will others. The OP doesn't say where he is located as maybe there is a gift one available that can be cannibalised for an uncracked pump housing. I have one such on board here in Cowes (Island Harbour Marina) but have no transport to get it to a post location. We had to have our ensuite one rebuilt (during a full pipework, seacock replacements and holding tank revamp) from a spares kit a month or so back as there was a dearth of new pumps available. oh and despite thinking keeping an old one as a spare to rebuild at leisure I have never actually bothered. to do so.

 

[Poignard]

I guess the only way to do it would be by 'welding' the crack in some way but, like others, I couldn't be bothered unless a spare was unavailable.

 

[vyv_cox]

I guess the only way to do it would be by 'welding' the crack in some way but, like others, I couldn't be bothered unless a spare was unavailable.

I found years ago, the hard way, that it is just about impossible to seal a leak in anything from the outside. I have welded plastics many times but on the outside of any kind of pressure vessel repairs were short-lived.

 

[Richard10002]

The cost of a complete new pump assembly is not a great deal more than a spares kit. Just buy a new pump and bin the old one.

Having faffed about with these pumps and service kits for couple of years, (a long time ago), I'm in the "buy a new pump" camp, even if it's for a spare, rather than immediate fitting.

 

[Oily Rag]

Many thanks all. The vote was for buying a new one and that's probably what I'll do. But with the "P" in PBO in mind, and Viv's comment about the difficulty in sealing from the outside, I tried sealing from the inside.

The stuff I used is called Bondic and comes with a UV source to cure it. As seals go, it looks OK. I can't scratch it off with a fingernail and it seems fairly well attached. Worth having on board for similar plastic repairs perhaps.

Thanks again.

 

[peteK]

Find some white pvc pipe a little larger diameter than the pump pipe and split it along its lenght ,spring it on over the pump with some sikaflex or similar and clamp it in place making sure the join is were you can't see it,if the pvc pipe is same length as pump pipe you wouldn't see its been repaired.

 

[BB1]

Find some white pvc pipe a little larger diameter than the pump pipe and split it along its lenght ,spring it on over the pump with some sikaflex or similar and clamp it in place making sure the join is were you can't see it,if the pvc pipe is same length as pump pipe you wouldn't see its been repaired.

LOL